A choice of radionuclide: Comparative outcomes and toxicity of ruthenium-106 and iodine-125 in the definitive treatment of uveal melanoma

Purpose: Both iodine-125 (¹²⁵I) Collaborative Ocular Melanoma Study and ruthenium-106 (¹⁰⁶Ru) eye plaques can achieve excellent tumor control in patients diagnosed with uveal melanoma. We analyzed our single institutional experience in the management of ocular melanoma treated with either ¹²⁵I or ¹⁰⁶Ru plaque brachytherapy. Methods and materials: The records of 107 patients with uveal melanoma treated with either ¹⁰⁶Ru (n = 40) or ¹²⁵I (n = 67) plaque brachytherapy between 2000 and 2008 were retrospectively reviewed. Tumor control parameters and toxicity were assessed. Results: Actuarial 5-year rates of local control, progression-free survival, and overall survival with ¹⁰⁶Ru were 97%, 94%, and 92%, respectively. For ¹²⁵I, these values were 83%, 65%, and 80%. In the subset of patients with tumor apex height ≤5 mm (36 ¹²⁵I and 40 ¹⁰⁶Ru), there was no difference in overall survival; however, progression-free survival was significantly improved with ¹⁰⁶Ru (P =02). Enucleation-free survival was significantly different between the 2 subsets, with no enucleations in the ¹⁰⁶Ru cohort (P =02). Patients treated with ¹⁰⁶Ru experienced reduced retinopathy (P =03) and cataracts (P <.01). Conclusions: Both ¹²⁵I and ¹⁰⁶Ru eye plaque brachytherapy treatment result in encouraging tumor control for patients with uveal melanoma. We demonstrate that ¹⁰⁶Ru offers these benefits with reduced toxicity in patients treated for uveal melanomas ≤5 mm in apical height.